The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 08, 1994
Filed:
Apr. 02, 1993
Rudolf Aigner, Burgkirchen, DE;
Guillermo Maier, Haiming, DE;
Rainer Muller, Burghausen, DE;
Hubert Seitz, Burgkirchen, DE;
Hoechst Aktiengesellschaft, Frankfurt, DE;
Abstract
A process is described for the preparation of aqueous solutions of betaines of the formula ##STR1## in which: R.sup.1 is an alkyl radical having 6 to 22 carbon atoms or is a radical of the formula R'CONH(CH.sub.2).sub.z --, in which R' has the meaning of R.sup.1 and z is 2, 3 or 4, R.sup.2 is an alkyl radical having 1 to 4 carbon atoms or is a radical of the formula --(CH.sub.2).sub.m --OH, in which m is 1, 2 or 3, R.sup.3 is an alkyl radical having 1 to 4 carbon atoms or is a radical of said formula --(CH.sub.2).sub.m --OH and y is 1, 2 or 3. The aqueous betaine solutions are prepared by quaternization of the corresponding tertiary amines with an .omega.-halocarboxylic acid and with an alkali metal hydroxide in the aqueous phase. The quaternization is carried out continuously in two or three stirred tanks arranged in a cascade, defined process characteristics being maintained in each tank. Using the novel process, aqueous betaine solutions are obtained in high yield and purity in a simple manner.